I installed these on a Gretsch G5420T Electromatic.
They somehow didn't need to tense after installing at all. I did pull them but not too much and they kept pitch right away.
They maintained the intonation outstandingly well.
Tonewise: The sound of the 3 first strings is gonna be duller (Like an upright bass) because the lack of winding results in less harmonics, for Jazz this means the strings are more homogeneous form first to sixth and overall better for soft chords and avoid string friction sounds.
It helped with my thumb pick a lot, no more "grit grit grit" while playing.
They do have some small texture but is much softer than roundwound. I suggest to lubricate them right before use for smooth glides.